My 96Q45 uses a variable displacement compressor-pretty exotic for its time,now the technology is more common on moderately priced cars- compressor never cycles off so you avoid the change in idle speed/power output normally felt as a compressor cycles. [/quote
This is used on some Lexus rides as well and is not the best method in that compressor failures are much higher and the compressors are rediculously priced. Most Asian rides still use the simple thermister on the evaporator coupled to a A/C control module. Not rocket science but it does work reliably.A/C techknowledge is at it pinnacle on Asian rides but it has come at the price of reliability and durability. It was nothing for an older Corolla to have 300K on it and the air would run 28-35 degrees at the vent never having even freon added to it. Ditto for the older Nissans that had the Calsonic supplied air systems.We just did not do a/c repairs on older Maximas,Hardbody trucks ect.. that had the simple systems. Calsonic was an excellent supplier. Denso has had some compressor failures on Lexus and upscale Toyota/Honda applications because the customer generally ran the climate control constantly which meant the compressor ran all the time even in winter. When we purchased our last new Honda I intentionally got one that did not have automatic climate control on it. As a life-long Honda/Toyota/Nissan tech I saw much better longevity from the standard a/c systems. It was the same in spades when I got my start working on domestic cars. The increase in head pressures that came with 134-A and the neccessity of the compressor running almost constantly on Automatic climate systems has put many comressors in an early grave. Some compressors now cost more than what you can buy a complete engine for the same vehicle. That's stickin to the poor old workin'man. I did an a/c repair on an older Q-45 that was near 3 grand when all was done.Same on an LS-400. Most of it you can thank the big-brother mentality that seems to be so vogue at this time.